1. Field of the Invention
The present invention relates generally to a pen-type input device and an input method using the same, more particularly to a pen-type input device for performing both a character input function and a mouse function, and an input method using the same.
2. Description of the Related Art
A pen-type input device, which performs tracking using an optical sensor and a relative coordinate system usually operates in a character input mode and a mouse input mode. When it is in character input mode, it will record tracking information both when the pen moves on a surface (e.g., a mouse pad) and when it moves above the surface. Without such tracking, character input may not be correctly performed.
FIGS. 1A and 1B show how to input (enter) characters using a general pen-type input device. Referring to FIGS. 1A and 1B, after each stroke of a character is input, the pen should be lifted up and moved to a start point of the next stroke to input the next stroke, as shown in FIG. 1A.
FIG. 1B shows the character input results that may be obtained when the pen-type input device does not recognize the tracking information of the pen while the pen moves above the surface (the mouse pad), in character input mode. If movements of the pen cannot be sensed while the pen is lifted up from the surface and moved, the next stroke starts at the last point of the previous stroke, causing character input error.
In the character input mode, the pen-type input device acquires input information by turning on a switch from the beginning to the end of each stroke while the pen is moved in contact with the surface. Afterwards, it should stop acquiring information by turning off a switch after completion of the current stroke and wait for the next stroke. However, even in this case, location information of the pen should be continuously measured to exactly perform character input by aligning the next stroke with the current stroke.
Mouse mode, in which a mouse function is implemented, is different from the character input mode. Generally, a user holds a mouse, against the surface of the mouse pad. If the mouse is placed on an edge of the mouse pad, the user lifts up the mouse and moves it to the center of the mouse pad to use it again. When the mouse is lifted up and moved in this way, the cursor or mouse pointer on the display does not move correspondingly. This allows the user to use the mouse with his arm placed in a comfortable position.
Problems may occur when a pen-type input device provides both a mouse function and a character input function. In a character input mode, even when the pen is lifted up from the surface of the mouse pad and moved, the location information is recognized and consequently moves the cursor. However, in mouse mode, the cursor is not moved when the pen is lifted up from the surface and moved. Therefore, in the case of character input, the pen's location information is recognized to move the cursor even when the pen is lifted up from the surface and moved. When a character input mode pen is used for a mouse operation, the mouse cursor is moved even when the pen (or mouse) is lifted up from the surface and moved, so the user may not use the mouse in a comfortable position. In contrast, when using a mouse mode pen for character input, the mouse cursor is not moved when the pen is lifted up from the surface and moved, thus it is not possible to exactly draw characters using the pen as shown in FIG. 1B.
In the conventional pen-type input device like the pen mouse, the character input and the mouse functions are not separated. Because of the above contradictory situation, the conventional pen-type input device may not smoothly perform both functions.
In the conventional pen mouse, if the pen is lifted up from the surface by a certain distance or more, the cursor position is not tracked, and in the character input mode or the mouse mode, if the pen tip is pressed with a predetermined force, with the pen mouse in contact with the surface of the mouse pad, a switch is operated to perform a mouse left-click function.
Because tracking is not performed when the pen is lifted up from the surface a user having the habit of lifting up the pen to some height during inter-stroke, inter-character and inter-word movements in writing text, may fail in the character input operation as shown in FIG. 1B. In this case, the user needs to practice writing characters without excessively lifting up the pen. In addition, to activate the switch during character input, the user must inconveniently press the pen with predetermined force.
Meanwhile, for a pen in mouse mode, when the user moves the pen mouse on the surface he must carefully handle the pen mouse so that the switch mounted on the pen tip does not operate. Therefore, if the hardware is configured to operate even though the pen contacts the surface with less force, ensuring easy character input in the character input mode causes normal mouse operation to become more difficult. That is, in the conventional pen-type input device, if the operation height characteristic and the sensitivity of the pen tip switch are improved to increase performance of the character input operation, the mouse operation becomes significantly more difficult.